Spirit-level.



No. 666,843. Patented .Ian. 29, |90l F. A. BRUWNELL. SPIRIT LEVEL.

(Applicgt ion filed July 2, 1900.)

(No Model.)

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UNITED STATES PAT NT @FFICE.

FRANK A. BROWNELL, OF ROCHESTER, NEW YORK, ASSIGNOR TO THE EASTMAN KODAK COMPANY, OF SAME PLACE.

SPIRIT-LEVEL.

SPECIFICATION forming part of Letters Patent No. 666,843, dated January 29, 1901.

Application filed July 2, 1900. Serial No. 22,271. (No model- To all whom it may concern:

Be it known that I, FRANK A. BRowNELL, of Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improvements in Spirit-Levels; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the reference-u u merals marked thereon.

My present invention has for its object to provide an improved leveling device adapted particularly for application to photographic cameras and by means of which the user may readily determine when the instrument is held in a horizontal position, although the device may be used for other purposes; and to this and other ends it consists in the improved construction hereinafter described, which is cheap, simple, and effectually prevents leakage of the spirit contained in it, the novel features being pointed out in the claims at the end of this specification.

In the drawings, Figure 1 is a plan view of a leveling device constructed in accordance with my invention; Fig. 2, a sectional View thereof, and Fig. 3 a perspective view of the parts separated.

Similar reference-numerals indicate similar parts.

The main frame or casing of the instrument is preferably constructed of metal and embodies the ring or body 1, having at the upper end an internal and slightly recessed overhanging flange 2, and atits outer edge is provided an attaching-flange 3, provided. with screw apertures, as shown, said external flange being in the present instance located at the top, so that the device as a whole may be let into the top of a photographic camera with the upper surface substantially flush. The ring-frame is provided with the internal screw-thread for the reception of a clampingring 4, screwing therein and engaging a flange or shoulder 5 on a hollowed back or cover 6, recessed at the front and provided with a small central aperture 7 The recessed face of the back or cover 6 is preferably polished, as by plating, so that the bubble in the liquid contained between the cover-plate and the front cover-glass 8 may be readily centered over said aperture when the instrument is held in a horizontal position. The cover-glass 8 is slightly hollowed or recessed in its under side and is arranged between the front edge of the plate 6 and the internal flange of the body portion, packing-rings 9, of soft rubber or other suitable packing material, being arranged on opposite sides of the glass, as shown. By screwing the ring 4 into the body the parts are securely clamped, making a liquid-tight joint between the glass and main frame and also between the glass and the cover and preventing any leakage of the extremely volatile alcohol or similar fluid which is placed in the device. A small aperture in the back of the cover-plate communicates with a relatively larger aperture on the under side, which is threaded and receives a small screw 11, a suitable metallic washer l2 and a rubber packing-washer 13 being interposed between the screw and the overhanging edges at the rear of the small aperture in the rear plate 6.

In assembling the parts of the device one of the packing-rings is placed in position on the overhanging flange 2. Then the glass is inserted, then the other packing-ring put in place, then the back plate placed thereon, and finally the ring 4 is screwed down, tightly clamping the parts together. Then alcohol or other liquid is poured into the small aperture in the rear plate, which is then closed by the screw, the liquid-space not being quite filled, so as to form a small air-bubble necessary to form the index cooperating with the central aperture, as will be understood.

The device described is very simple and, as I have determined, practical, and,furthermore, the joint with the glass is such as to absolutely prevent the leakage of the liquid, a fault common in nearly all devices of this general description, and as the back or cover plate is not rotated on the packing-rings in clamping the parts there is no liability of wrinkling or disturbing said packing-rings but the surfaces are forced squarely in contact by the I tore, the screw for closing it, and the flange clamping-ring screwingin the frame from the rear side.

The device as a Whole is small and can be readily let into a small recess in a camera.

I claim as my invention- 1. In a level,the combination with the ring-' frame having the internal flange, the glass, and the back plate, of the packing-washers between the glass and the flange, and between the glass and back plate, and a single screw device rotatable independently of the ringframe and the back plate, and engaging both, for clamping the parts togetheix 2. In a level, the combination with the ringframe having the internal flange and the threaded rear portion, the glass and the recessed back plate having the flange at the front, of the elastic packing-washers between the glass and the flange in the frame and the back plate, and the threaded clamping-ring screwing in the ring-frame and engaging the back plate but turning independently thereof to clamp it and the glass firmly in position.

3. In a level, the combination with the ringframe having the internal flange and the threaded rear end, and the glass, of the recessed back plate having the central aperat the edge, the packing-rings on opposite sides of the glass, and the clamping-ring operating in the ring-frame and bearing upon the rear side of the back plate.

4. In a spirit-level, the combination with the ring-frame having the internal flange, the glass, the recessed back plate having the central index, the packingrings between the glass and the ring-flange and back plate, and a clamping device having a screw connection with the ring-frame and operating upon and turning independently of the back plate to clamp glass firmly and form a liquid-tight joint.

5. In a level, the combination wit-h the ringframe havingtheinternal and external flanges and the threaded rear portion, the glass and the packing-rings on opposite sides thereof, of the recessed back plate having the external flange, the Central recess and the screw for closing it, and the threaded clamping-ring engaging the ring-frame and operating upon the flange on the back plate.

FRANK A. BROWNELL.

Witnesses:

F. F. CHURCH, G. A. RODA. 

